1. Field of the Invention (Technical Field)
The invention generally relates to aspirators which are used for removing body fluids from accident victims and other patients during their transportation to medical facilities in motorized ambulances. More particularly, the invention relates to a fixture with aspirator components and which is adapted for mounting on an internal wall in the patient transport area of an ambulance.
2. Description of the Related Art
The design of medical equipment used in treating patients that undergo transportation in an ambulance is, in many respects, limited by the electrical generating and storage facilities provided by the chassis suppliers. The standard automotive electrical system which is provided by the chassis supplier must be converted by the ambulance manufacturer to an ambulance electrical system that can handle the added load requirements imposed on the power supply under the emergency conditions encountered.
Ideally, the ambulance electrical system should be capable of handling (1) the chassis loads (i.e., the starter, ignition, basic chassis lighting, and driver cab air conditioning loads), (2) plus patient module or compartment loads (i.e., transport area lighting, air conditioning and life support loads including those for ventilators, suction units, ECG monitors, defibrillators, and infant transporters), and (3) emergency system loads (i.e., flashing, spot and other emergency lights, as well as sirens, horns and communication equipment loads).
Realistically, the load demands have in the past caused, and continue to cause, some serious difficulties. In the normal non-emergency environment, the electrical generating system (i.e., the alternator) has been adequate to handle the chassis and battery charging loads. On the other hand, in the emergency environment, the generating system has usually been found lacking in capacity. As such, battery discharge has been a common occurrence under many emergency conditions and has been known to lead to a complete battery discharge causing a cessation of operation of the ambulance motor and a consequential inability to use on-board life support units.
These electrical load demands, in the light of limitations imposed upon the ambulance manufactures by the basic electrical systems provided by the chassis supplier's, have led to a need (1) for better electrical system designs by the ambulance manufactures, (2) for better load management by those involved in the day-to-day use of the ambulances and the life support equipment and facilities provided for use by the emergency medical technicians (EMTs), and (3) for better designs of the life support equipment and facilities provided the EMTS.
Ambulance electrical system designs in the past couple of decades have centered on increasing electrical generating capacity through the use of larger and sometimes dual alternator systems, and on the use of dual maintenance--free batteries having higher cold crank and reserve capacity ratings.
Load management has improved (1) by eliminating, and reducing the use of high load consuming equipment and substituting equipment with lesser load demands, (2) by more effectively utilizing load usage indicators and protective devices, and (3) by providing better educational programs for the equipment users involved in the emergency medical services (EMS).
Life support equipment designs have also improved. Suction, ECG monitors, defibrillators, and ventilators are now commonly portable and operated by self contained power packs which involve the use of replaceable and rechargeable 12 V DC battery systems. Such packs are usually equipped with a battery charger that is designed for specific use with the unit involved, and provide for connection with a 110-115V AC power source (i.e., shore tie or on-board inverter). Use of the power packs has relieved the load demands on the ambulance electrical systems to some extent but imposed a need for 110-115V AC outlets in the patient transport area so as to provide convenient recharge power at the equipment storage point in the ambulance. The recharge power source can be from either or both a shore tie to a land based power system or through a connection with an on-board inverter. When a power pack requires recharging during transport and replaceable batteries are unavailable, the attendant must resort to the on-board inverter.
The problems associated with the presence of a high voltage AC power source in the environment of the action area of an ambulance are well known and apparent from a consideration of pages 65-71 of Report No. DOT-HS-7-01801, dated JUNE 1979, entitled "AMBULANCE ELECTRICAL SYSTEM STUDY", and prepared for the NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION OF the U.S. DEPARTMENT OF TRANSPORTATION by Parker, Starmer, West and Ruddle.
As indicted therein suction equipment provides a conductive path during use which could connect the patient to an electrically active circuit. For example, suction fluids, depending on ion content, can exhibit a variety of conductivities, and thereby establish a conductive path to a patient if the fluid in the suction system gets crossed up with a shore or on-board 112-115V AC electrical source. Furthermore, blood from a wound can provide a conducting path that can connect the patient to a number of nearby conductive structures. The hazards involved in the inadvertent dumping of an aspirator canister's contents under the conditions encountered in real time emergency patient transport to a hospital facility are real.
In addition, the electrically powered devices with internal rechargeable batteries can also be inadvertently tied together through the battery charging circuitry as well as being connected to the patient. Therefore, it is important to recognize that isolation of electrically powered devices is not a most viable option for minimizing accidental electrical shock.
Although there are opportunities for both patient and attendant to receive shock in the environment of the patient transport area, it is recognized that the magnitude of the shock will be safely below that necessary to induce cardiac arhythmias provided the maximum voltage encountered is nominally 13.8 volts. Such of course is the maximum voltage available from the DC system of todays ambulances.